1. Field of the Invention
This invention generally relates to scalable stroke fonts, and in particular relates to a system and method for creating scalable stroke font data and storing scalable stroke font data on a mobile computing device (“mobile device”).
2. Background
Text data, such as font data, is typically stored in a memory in a mobile device. Because the mobile device typically has relatively limited memory and processing resources, the amount of text data stored on the mobile device and the text rendering capability of the mobile device is often limited.
There are three basic font types: Bitmap, Outline and Stroke. Bitmap fonts are stored as graphic images of characters with each point size of a typeface stored as a separate font. Each character is stored as an array of pixels (a bitmap). Bitmap fonts require a relatively large amount of storage space, and it is relatively difficult to scale or apply effects to this type of font.
Outline fonts, such as TrueType™ fonts, are produced from information about the shape, or outline, of the glyphs. The outline is defined as a set of lines and curves. Outline fonts facilitate scaling and other effects better than bitmap fonts, and require less storage space than bitmap fonts. Many mobile devices, however, typically do not have the storage space and processing requirements to adequately facilitate the use of outline fonts.
Stroke fonts are those in which the shapes of the characters, as represented by glyphs, are represented by strokes. A stroke is typically defined by a line and curves. The storage space required for stroke font data for a given set of glyphs is typically much smaller than required for corresponding outline font data. Stroke fonts, however, typically produce glyphs with impaired quality as compared to outline fonts. Thus, existing rendering engines that render stroke-based fonts produce glyphs of relatively limited quality.